You should get your own equipment, DSLR underwater is not exactly light and easy to handle when you're concentrating on shooting, the last thing you want is to fumble with your dive gear and buoyancy while shooting
So, get your own gears, get familiar with it then go into shooting,
if you cannot get your buoyancy right, then don't shoot, its ok if you hurt urself, but if u kill corals then its not very nice